Vitrified clay pipe joint



C. V. McCLINTOCK VITR'IFIED cLAY PIPE' JOINT Filed July 21, 1945 Aug. 3 1, 194s.

Patented Aug. 3l, 1948 VITRIFIED CLAY PIPEI JOINT Cecil V. McClintock,y Whittier, Calif., assignor to Pacific Clay Products, Los Angeles, Calif., a corfporation of California Application July 21, 1945, serial No. 606,387 5 claims. (cl. 285-1153) My invention relates to Iceramic or clay composition products and particularly articles in the form of pipe connections and a method of producing them.

The production of burned clay products is an old art and widely practiced. As a result, the art has long recognized two particular means of forming a shape from clay composition and subsequently burning it at a suitable temperature to mature the clay. The oldest known method of forming the clay has been to pressure Imold it to shape. This method is limited to the molding of symmetrical objects and cannot be used where the object has a transverse iin, shoulder or lip intermediate its ends.

Another commonly used method of making shapes from clay material is the extrusion method. By this means the clay material is pressed through an orifice die which imparts outside shape or form to the'product being made and which may be provided with a core so that hollow objects can be extruded.

With both of these methods certain limitations are encountered and it has been found relatively expensive to mold clay shapes having interior.

projections intermediate the ends.

With this in View, it is among the objects of my invention'to provide a new and improved vitrifled clay product and method of forming the same by means of which an inwardly extending projection may be incorporated in a pipe-like form without it being necessary to provide a core of intricate shape.

Another object of my invention'is to provide a new and improved vitrifled clay object and method of forming the same which is rapid and economical and in which relatively few of the molded objects are broken prior in a kiln for baking.

Still another object of my invention is to provide anew and improved vitried clay product having van inwardly lextending flange intermedito being placed late the ends wherein the flange and the wall of It will be apparent from the accompanying drawings and the following descriptionthat while many of the elements of structure and method are familiar to the art of making clay products, Iold elements and new have been marshaled` together to produce a new and novel ceramic product incorporating novel steps in the formation of the article prior tro-baking or burning entirely distinct from anything heretofore produced, easy to fabricate and operate, more efficient than previous methods `and having a usefulness which will continue indefinitely.

In the drawings: f

Fig. l is a side elevational view of a pipe joint incorporating the novel connection.

Fig. 2 is a longitudinalsectional view of the pipe joint shown in Fig. 1.

. Fig. 3 is a cr-oss section taken on the line Ill-III of Fig. 2.

Figs. 4, 5, 6', andl are diagrammatic illustrations of the various steps in the process of forming the article prior to baking or burning.

It will, of course, be appreciated by those skilled in the art that the use of extrusion processes with `and without cores and the use of cores and molds in forming plastic material into shapes for baking are well established and well known. It will also be appreciated, in View of the universally accepted methods having been proven and in use for afgreat length of time, that innovations or even slight changes from accepted practice seldom nd their way into the art. As in so many arts where material is cheap, the time element required in the production of the parts prior to molding has heretofore not been considered as of great importance. The breakage of molded forms has likewise been considered of secondary character in view of the readiness and ease with which they have been made.

There are, however, some forms in which the breakage may be high and it has also been found that time saved in the making of forms where little or no breakage is encountered has a material effect upon the economy of manufacturing operations lover a period of time. Moreover, with the increasing cost of labor, material and production methods, a vitried clay pipe joint which Ican be more inexpensively manufactured than heretofore and which can be made also of an improved design is highly desirable.

In the embodiment chosen to illustrate lmy invention there is shown a pipe joint in which the The change is effected by means of a pipe joint 3 or fitting I4 frequently termed an increaser. It will be noted that the large pipe section has a bell end I5 in which one end I6 of the increaser is inserted and that the opposite end I'I of the increaser has the nature of a bell end into which the smaller pipe is inserted. A suitable packing I8 is provided in each cas-e. The increaser itself has a uniform cylindrical outside diameter slightly larger than the outside diameter of the small pipe and approximately the lsame or slightly smaller diameter than the outside diameter of the large pipe I2. The particular embodiment shows a cylindrical pipe but it will be appreciated that pipes of other shape are also contemplated.

On the interior of the increaser is provided an annular projection. 2li, one side 2| of which is flat and transverse to the axis of` the joint and the other side 22 of which is provided with a slope of approximately 45 in the form illustrated. Intermediate the sides 2| and 22 there is a cylindrical connecting portion 23' having a diameter approximately the same as the inside diameter of the small pipe Ill,

The inside wall 24 of the increaser on the side thereof adjacent thev sloping side of the projection is cylindrical in shape, that is to say without draft, and` has a diameter substantially the same as that of the inside ofthe large pipe.

The interior of the increaser on the side adjacent the flat face 2l ofthe projection has an outward flare 25. All parts of the ared interior are substantially greater in diameter than the outside diameter of the small pipe in order to provide for the packing I8.

In forming the articley a combination of an extrusion and a molding process is used as illustrated in Figs. 4, 5', 6, and '7. An extrusion machine 33 of any suitable type has a body portion 3l from which a claycomposition 32 is normally forced through a die 33 providing on its interior a part 34' which is cylindrical in cross section. Within theport is a stationary core 351' of the usual sort which may be held in place by meansl of a spider. The core has the customary conical end 35i in order to divide the clay material as f it enters the port and in this embodiment has an undercut outside end 31.

Adapted to cooperate with the extrusion die is a form 38 which has a frusto-conical' base 39 and a cylindrical upper element MI, the diameter ofthe cylindrical element being smaller than the small end' of the frusta-conical base'. The form is carried' by a platen lII. of a somewhat larger'` diameter than the lower end ofthe die. In. this embodiment the form and platen are adapted 1- to be moved' vertically into place by means of a hydraulic cylinder 4'2'or other controllable means. In the schematic representation, the platen is movedl by piston rod 4'3 leading toa piston within the cylinder'. A hydraulic line 44; is adaptedv to provide hydraulic duid on one side of the cylinder for a quick removal of the platen, should that be, desired. A hydraulic line 45 provided. with a needle valve 4,5 is adapted to supply hydraulic. duidV to the cylinder for lifting the platen and form into= place. and for subsequently permitting the hydraulic liquid to leave the cylinder at a measured rate when thet platen and form arel lowered.

In operation, clayv composition of suitable type is pressed` (as by' an auger; large piston' or theV like) in order' to extrude it outwardly through the annular' space between the wall of the die port and the wall of. the stationary cor-ex Norlmally this will result in a hollow cylindrical section.

After the clay has reached the outside end of the port and has been cut olf even by some convenient means such as a suitable wire, the form is raised to a position shown in Fig. 5. When in the `position there shown, the platen is ressed snugly against the outside end of the die. In this position also, the upper face of the cylindrical upper element ib of the form is pressed snugly against the flat lower face of the stationary core. With the form in this position, there is provided an annular space Il which extends inwardly from the wall of the extrusion port. Initially the space is empty but :pressure is exerted upon the clay material and it is forced lateraliy inwardly into the annular space, since the platen and form at this stage are held in place with suiiicient iirmness so that the line of least resistance for the clay material is into the annular space. This is the relationship of the parts and the clay material shown in Fig. 6'. Alfter the annular space becomes filled with clay material, the hydraulic pressure is released and 'continued pres-sure upon the supply oi clay material again. forces it gradually outwardly to the position shown in Fig. 7. When the platen il has been lowered to the desired point, a Wire lli-3 may be passed over the outside end of the vdie in order to cut ofi the formed object at a proper length.

It will be appreciated that any great amount of resistance oifered `by the platen III to the pressure used for extruding the clay material would :wa result in a bowing or distortion in the wall of the molded clay. To avoid this, the platen is permitted to lower at a rate just slightly less than or substantially equal to the rate of extrusion of clay material from the die. By this meansthere l is provided a slight resistance so that the formed material will remain compact without distorting until the wire cut-off separates the extruded portion from that remaining in the die. The lowering of the platen may be readily accomplished by a suitable adjustment of thev needle valve 46 which will permit the hydraulic fluid to` exhaust from the lower side of the hydraulic cylinder at a suitable predetermined rate. After the cut-off, if desired, the hydraulic cylinder may lower the platen at a more rapid rateby the introduction of pressure into the top sidel through the hydraulic line 44'. After the wire cut-oil has been effected, the molded part can be lifted from the platen and mold, driedv and burned. The fitting may be glazed if desired. It will be apparent that the portion of the mold which has been formed by extrusion only will have a cylindrical interior, whereas the portion formed by the mold, except for a very short cylindricals'ection, will have a bell-shaped -draw There has therefore been provided a molded article to be formedI into avitreous clay part in which simplicity of design has been retained while at the same time providing an interior shape and dimensions of a particular sort and a method for forming the same which incorporates two methods of forming previously practiced in a manner which is adapted to quickly and efficiently'forrnthe part to its desired shape.

I claim:

1. A clay pipe form having for its ultimate purpose the joining of a pipe of large size with apipe of smaller sizel comprising: anopen ended section having apartit'ioned interior wall, a par'- tition thereior intermediate the' ends of the section, said partition being in the form of an annular, inwardly extending projection having one side thereof iiat and transverse to the axis and the opposite side extending angularly outwardly toward the adjacent end, the interior wall section on the angularly sloped side of the projection being parallel to the axis and the interior wall section on the opposite Side of the projection having an outward are.

2. A clay pipe form having for its ultimate purpose the joining of a pipe of large size with a pipe of smaller size comprising: a section having an exterior wall and an interior wall, a projection extending throughout the circumference of the interior wall intermediate the ends dividing said interior wall into two sections, said projection having one side thereof flat and transverse to the axis, an opposite side extending angularly outwardly toward the adjacent end and an inner wall parallel with the axis separating said sides, the interior wall section on the angularly sloped side of the projection being parallel to the axis and the interior wall section on the opposite side of the projection having an outward flare.

3. A vitriiied clay pipe element adapted vfor joining a pipe of large diameter with a pipe `of smaller diameter comprising an annular section having a cylindrical exterior wall and an interior wall, an inwardly extending annular projection integral with and having the same density and porosity as the remainder of said element and located intermediate the ends of the element to divide said interior wall into two sections, said projection having one side thereof flat and transverse to the axis, an opposite side extending angularly outwardly toward the adjacent end and an inner cyllindrical wall separating sai-d sides, the interior wall section on the angularly sloped side of the projection having a cylindrical shape and the interior wall section on the opposite side of the projection having an outward iiare, the flat side of said annular projection being adapted to abut the plain end of a pipe while the outward flaring interior wall section of the element cooperates with such plain end pipe to form a pocket for the reception of sealing composition.

4. An open ended, integral extruded clay composition fitting for bell end pipe having a cylindrical outer surface of uniform diameter, an inwardly tapering inner surface contiguous to one fitting.

5. A iitting for ycoupling a bell-ended pipe with a pipe of smaller diameter, the said fitting including a tubular member having a cylindrical outer surface of uniform diameter, one end of said fitting being adapted to be inserted into the bell end of a larger diameter pipe and the .other end of the said fitting being adapted to receive the end of a smaller diameter pipe, the said iitting having an internal, inwardly extending projection intermediate the ends thereof, the said projection having a at side forming a shoulder for abutment with the end of the smaller pipe, the opposite side of said projection being beveled and forming a frusto-conical shaped chamber within said litting, the interior of the said iitting adjacent the pipe of larger diameter being cylindrical in shape and of substantially the same diameter as the inner diameter of the larger pipe, and sealing means interposed between the outer surface and inner surface of the tting adjacent the ends of the larger pipe and smaller pipe, respectively.

CECIL V. MCCLINTOCK.

REFERENCES CITED The following references are of record in the ldie of this patent:

UNI'I'ED STATES PATENTS 

